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fish, in zoology

(Encyclopedia)CE5 Anatomy of a ray-finned fish fish, limbless aquatic vertebrate animal with fins and internal gills. Traditionally the living fish have been divided into three class: the primitive jawless fish...

Eve, in genetics

(Encyclopedia)Eve, in genetics, popular term for a theoretical female ancestor of all living people, also known as Mitochondrial Eve. In 1987 biochemist Allan C. Wilson proposed that all living human beings had inh...

family, in taxonomy

(Encyclopedia)family, in taxonomy: see classification. ...

family, in sociology

(Encyclopedia)family, a basic unit of social structure, the exact definition of which can vary greatly from time to time and from culture to culture. How a society defines family as a primary group, and the functio...

farming, in agriculture

(Encyclopedia)farming, in agriculture: see agriculture. ...

farming, in taxation

(Encyclopedia)farming, in the history of taxation, collection of taxes through private contractors. Usually, the tax farmer paid a lump sum to the public treasury; the difference between that sum and the sum actual...

fatigue, in engineering

(Encyclopedia)fatigue, in engineering, microscopic cracking of materials, especially metals, after repeated applications of stress. Fissures may be formed within pieces of metal during their manufacture when, while...

fatigue, in physiology

(Encyclopedia)fatigue, in physiology, inability to perform reasonable and necessary physical or mental activity. Muscle fatigue, for example, results when the contractile properties of muscle are reduced, and conti...

elevator, in aviation

(Encyclopedia)elevator, in aviation: see airplane. ...

elevator, in machinery

(Encyclopedia)elevator, in machinery, device for transporting people or goods from one level to another. The term is applied to the enclosed structures as well as the open platforms used to provide vertical transpo...